SO-ARM 102
A printed leader–follower robot arm kit with a parallel gripper, designed for teleoperation and imitation learning.
Project documentation
Before you build
Five answers, each linked to its source
What does it cost?
Not documented
No cost in the reviewed sources.
Can I sell what I build?
YesCommercial use OK
Hardware CERN-OHL-P-2.0 · Software Apache-2.0. Licensing source
What’s open?
4 of 6CAD: AvailableBOM: AvailablePCB: Off-the-shelf partCode: Not documentedSim: AvailableGuide: Available
Code not documented · PCB off-the-shelf. All six files
Is it maintained?
Active
Latest activity Oct 29, 2026 · main repo last commit Oct 28, 2026 · 57 commits in the last 52 weeks · 5 contributors Activity
01 / Under the shell
The specifications.
Hardware, build and software on one sheet. Every fact links to where we found it.
SO-ARM 102 is a leader–follower robot arm kit for teleoperation and imitation learning. Each arm has five degrees of freedom plus a gripper. The parts are printable, with STL files and STEP sources provided; the BOM and assembly steps are also available.
Hardware
- Actuators
- 12 · Servos for one leader and one follower. bom.md
- Build
- 3D-printed · Parts are provided for printing. Documentation
- Degrees of freedom
- Each arm has five degrees of freedom plus a gripper. README
- Gripper
- Parallel gripper, 85 mm span. README
Building it
02 / The files behind the robot
What’s open.
Six parts of the build, each checked separately. Gaps stay visible.
| Part | Status | What’s there | License | Source |
|---|---|---|---|---|
| CAD | Available | STEP CAD sources are provided in the models directory. | Not documented | step/ |
| Bill of materials | Available | Bill of materials for the kit. | Not documented | bom.md |
| Electronics | Off-the-shelf part | The BOM lists Waveshare Bus Servo Adapters as servo controllers. | — | bom.md |
| Code | Not documented | Not documented | Not documented | No source found |
| Simulation model | Available | URDF and Xacro descriptions are provided. | Not documented | urdf/ |
| Assembly guide | Available | Assembly steps and a printable booklet are listed. | Not documented | assembly-guide.md |
03 / Know before you build
Can you sell it?
YesCommercial use OK
The hardware design is CERN-OHL-P-2.0. The code is Apache-2.0. You can build, modify and sell robots based on it, as long as you keep the license notices.
- Hardware
- CERN-OHL-P-2.0
- Software
- Apache-2.0
04 / The upstream project
Is it maintained?
ActiveLatest activity Oct 29, 2026, 1 day before the snapshot
The main repository’s last commit was Oct 28, 2026.
- Stars
- 175
- Forks
- 10
- Contributors
- 5
- Latest release
- v0.2.0 · Oct 22, 2026
Snapshot captured Oct 30, 2026. Recorded figures, not live metrics. Active: activity within 90 days of the snapshot. Quiet: within a year. Dormant: longer.
05 / Parts & kits
A head start.
Maker-listed sellers only. No affiliate links or paid placement.
MAKER’S COST
Not documented
No cost in the reviewed sources.
Kit availability is not documented in our reviewed sources.
06 / Side by side
Compare with other arms.
Other arms in the directory, most recently active first. Same sources, same rules.
| Robot | Cost | Open files | Can I sell it? | Runs on | Maintained | Stars |
|---|---|---|---|---|---|---|
| SO-ARM 102This robotRobonine | Not documented | 4 of 6 | YesHW CERN-OHL-P-2.0 · SW Apache-2.0 | LeRobot | ActiveOct 29, 2026 | 175 |
| Star Arm 102Fashion Star | Not documented | 5 of 6 | Check firstHW not documented · SW not documented | LeRobotROS 2Python | ActiveOct 30, 2026 | 60 |
| reBot Arm Base SeriesSeeed-Projects | Not documented | 4 of 6 | Yes, with creditHW CERN-OHL-W-2.0 · SW Apache-2.0 | ROS 1ROS 2LeRobot | ActiveOct 30, 2026 | 4,628 |
| Mini-ArmJonathan Shulgach | About $82Basic build | 5 of 6 | YesHW MPL-2.0 · SW Mozilla Public License 2.0 | ROS 2Raspberry PiPython | ActiveOct 23, 2026 | 14 |
| This robotSO-ARM 102 | Star Arm 102 | reBot Arm Base Series |
|---|---|---|
| Cost | ||
| Not documented | Not documented | Not documented |
| Can I sell it? | ||
| Yes | Check first | Yes, with credit |
| Open files | ||
| 4 of 6 | 5 of 6 | 4 of 6 |
| Runs on | ||
| LeRobot | LeRobot, ROS 2, Python | ROS 1, ROS 2, LeRobot, Isaac, Python |
| Maintained | ||
| ActiveOct 29, 2026 | ActiveOct 30, 2026 | ActiveOct 30, 2026 |
Upkeep is measured against each robot’s own snapshot. Costs keep the maker’s scope, so check what each figure covers.
See them in the table07 / Follow the evidence
Open books.
Repository files are pinned to commit e8ef998. Websites and papers are listed with their review dates.
- 01README.md at e8ef998Reviewed Oct 30, 2026
- 02DOCS-LICENSE.txt at e8ef998Reviewed Oct 30, 2026
- 03HARDWARE-LICENSE.txt at e8ef998Reviewed Oct 30, 2026
- 04SOFTWARE-LICENSE.txt at e8ef998Reviewed Oct 30, 2026
- 05docs/bom.md at e8ef998Reviewed Oct 30, 2026